Semiautomatic telephone system



Nov. 4 1924.

, 1,514,363 G. A. BETULANDER ET AL SEMIAUTOMATI C TELEPHONE SYSTEM 3 Sheets-Sheet 1 Filed Feb. 22. i921 AWE $8 $8 as E 3. r\ 12 m Nov. 4 1924.

G. A. BETULANDER ET AL SEMIAUTOMATIC TELEPHONE SYSTEM F l Feb 22 3 Sheets-Sheet. 2

Nov. 1924. 1

7 1,514,363 G. A. BETULANDER'ET AL SEMIAUTCMATIC TELEPHONE SYSTEM 3 Sheets-Shet 5 Filed Feb. 22 192 Patented Nov. 4, 1924.

UNITED STATES 1. 4. 3 PATENT oFF1ca'.-

GOTTHILF ANSGARIU S BETULANDEIt, OF SODERTORNS VILLASTAD, AND NILS GUN- NAB PALMGREN, OF STOCKHOLM, SWEDEN, ASSIGNO'RS TO THE RELAY AUTOMATIC TELEPHONE COMPANY LIMITED, OF vLONDON, ENGLAND.

SEMIAUTOMATIO TELEPHONE SYSTEII.

Application filed February 22, 1921. Serial no. 446,990.

To all whom it may concern;

Be it known that GO'ITHILF ANseARIUs BETULANDER and NlLs GUNNAR PALMGREN,

' for instance current impulses sent in various combinations over two or more line branches, alternating current impulses of different frequencies, or the like. Such switching systems have an advantage over the common systems in which the selectors are actuated by means of series of impulses, in that the speed of operation can be considerably increased, simultaneously as the inconveniences connected with the sending of current impulses'in rapid succession are entirely avoided. Thepresent invention relates to a switching arrangement adapted to regulate the sending of impulse signals according to the first-mentioned system by the control of a number switch. provided at the station, by means of which the: desired number is marked electrically. In full automatic systems, anumber switch of this kind may for instance consist of a register adapted to be actuated from the subscribers station, and adjusted inaccordance with the desired number, whereas in semi-automatic systems, the same consists of a key board; The invention is principally. characterized by the sending of the different impulse signals being controlled by a' number of code relays actuating a number of contact groups located in the impulse circuit and corresponding to the different digits of the number system employed, the circuits of said code relays being in turn controlled partly by the said number switch, and partly by a sequence switch which regulates the actuating of the said code relays in the proper succession in such a manner that the impulse signals corresponding to the difi'erent digits of the subscribers number are sent out in proper order, according as the sw1tching progresses.

The invention .will be explained more fully hereinbelow, with reference to the accompanying drawings which illustrate the invention as applied to a semi-automatic telephone system in which the connections are established only by means of relays.

Fig. 1 shows the arrangements at the operators position. KS' denotes the key board, KM ,KM, the electro-magnetstby means of which'the keys are retained in their depressed position, CE -OR, the va rious code relays, and FS the sequence switch which in the example shown comprlses a number of switching relays FR FR and an impulse relay IR. HS designates 'an auxiliary switch comprising a number of shifting relays OR,-OR and a cut-ofi' relay UR, the said auxiliary switch controlling the sending of the different current impulses. TT is the operators telephone apparatus which is connected to a speaking key E0. 7

Figs. 2 and 3 show the arrangement in a group switching section. The incoming trunk lines FL are connected over link lines 'ML to the trunk lines GL going to the next switching section, by means of switching devices of the kind described in our Swedish Patent No. 49,816, dated April 2, 1919, pat-. ent application No. 1517/1919/. The connections between the lines FL and ML are thus established by means of a'number of connecting relays A R corresponding to the various trunk lines FL, and by a number of marking relays M R corresponding to the various link lines ML,'by energizing the relays corresponding to the lines that are to be connected with one another. The marking relay M R then effects such a mechan-- lished between the link lines ML and the outgoing lines GL by means of a number of connecting rela s A R corresponding to the various link lines, and by a number of marking relays corresponding to the diiierent outgoing lines. 7

The outgoing trunk lines GL are divided in a common manner in a number of numerical groups whichmav be selected by means of a group selector V which is common to a plurality of incoming trunk lines FL, the said group selector GV comprising a number of combination relays SR,SR, and a control relay HR,. The testing of the various outgoing trunk lines belonging to the selected group is effected by means of a testing device PS comprising a number of switching relays KR,KR and two test relays PR and PR This testing device is so arranged as to test the various lines in pairs, in that the different switching relays switch difierent pairs of test wires PL successively to the two test relays PR, and PR the test relay which is switched to a disengaged line attracting its armature and stopping the switchin operation.

Accor ing to the code system used in the present case, each digit is denoted by an impulse combination comprising two combination impulses sent outsuccessively over the two speaking line branches a, b according to the following scheme:-

First Second impulse Digit Impulse 7 a holding circuit 10, whereupon the searcher is released. On the relay DR attracting its armature, a circuit 11 is closed through a relay BB which then attracts its armature and closes a circuit 12 through a relay BR which in turn closes a circuit 13 through the holding electromagnets KM of the key BR lights a call lamp board. The rela ARL indicating tliat a call has been received at the operators position. Now the telephone operator receives the desired number and preses the corr pon ing k ys, whereupon the operator actuates a starting key SK so as to close a circuit 14 through a relay TR, and a relay NR which are both brought into operation. On the first-men tioned relay attracting its armature, the

same switches itself into a holding circuit over a relay BR which attracts its armature and cuts out the starting key. On the relay NR attracting its armature a circuit 15 is closed through the selector-connecting relay R, belonging to the trunk line FL ,whereby the. two speaking line branches of the trunk line are connected to the group selector GV. At the same time the'relay V R closes the circuit of relay ER which in turn closes a circuit 16 through the control relay it be assumed that the first digit of the desired subscribers number is 0. Now the code relay OR closes the circuit 20 for the first switching impulse, which current impulse passes over the line branch at and energizes partly the relay OR of the auxiliary switch FS, Fig. 1., and partly the combination relay SR of the group selector. The first-mentioned relay then locks itself over its contact 21. At its contact 22 the latter relay switches in the relay SR which is slow to release and -s0 indicated on the drawings by the rectangle placed between the winding and the armature, as shown in Fig. 3', which relay closes a circuit 23'through the relay SR the last-mentioned relay locking itself over its contact 24 and closing a circuit 25, whereby the relay HR will be short-circuited. On

account of this the relay HR releases its 3 armature, thus breaking the switching impulse at its contact 26' and simultaneously closing a circuit 27 through the relay SR which at its contact 28 interrupts the short circiut of the relay HR, so that this latter again attracts its armature. Prior to this, the relay SR has locked itself over its contact 29. I v On interrupting the first switching impulse, the relay OR Fig. 1, releases its armature. Prior to this, however, the relay OR t-was energized in a circuit 30. When the relay OR now releases itsarmature, the

relay ORQis still retained energized over a current path 31 containing'the shifting relay OR, which short-circuited as long as the relay OR was current carrying, but which isnow brought in o er tion so as to close 'the circuit 32 for the other switching impulse, the said current path 32 containing the shifting relay 0B,, and also the combi' nation relay SR, in the group selector, Fig. 3. The'last-mentioned relay now closes a circuit 33 through a relay G R- and the marking relay M R The relay G R switches all test wires for the lines G L in the group thus selected to the testing device PS which is started by the marking relay M R closing a circuit 34 through the first switching relay KR in the testing device. If it is assumed that the first two lines are engaged, the next switching relay KR will be immediately energized over the current path 35, whereby the next pair of test wires are switched to the test relays PR andPR If it is assumed that the third trunk line -GOL3 is disengaged, the test relay PR is now energized in a current path36 containing the working winding AL of the vtest relay PR A contact 37 in the circuit ofthe operating winding of the connecting ML over,- the group of contacts K G rentless.

relay A,R and the markingrelay M R, The relay A R attracts its armature and connects the link line ML to the outgoing trunk line G L over the group of contacts K G At the same time the marking relay M R closes a circuit 39 for the connecting relay A R which attracts its armature so as to connect the trunk line FL to the link line whereby the connection is completed till the next switching section in which the trunk line G0L3 is immediately connected to the corresponding group selector through the selector-connecting relay V,R contained in the circuit 39. The connecting-relay A R breaks the circuit of the selector-connecting relay V,R wherebyfthe group selector GV is cut out. The second switching. impulse is then interrupted at the contact 40, and at the same time the circuit of the relay ER is broken at the contact 4 whereby all relays of the group selector are rendered cur- The battery having again been connected to the selector-connecting relays V R by the deenergizing of the relay ER,,

which is slow to release as indicated by the rectangle shown in Fig. 2, the group selector is in readiness for receiving a new call.

When the second switching impulse was interrupted, the relay-OR,, Fig. 1, was deenergized. Prior to this, however, the relay OR was energized overa current path 42, the said relay having thus locked itself over its contact 43. When the relay OR is now.

releasing its armature, a circuit 44 isconsequently closed through the impulse relay IR which again closes a circuit 45 throng the second relay FR, of the sequence switch and,- assumin the second digit of the subscribers num er to be 1, through the code relay CR At the same time, hb'wever, a.

circuit 46 is closed through the cut-off relay UR, whereby all the relays of the auxiliary switch and the impulse relay IR are ren- The second group selector is now actuated by two combination impulses sent out in succession, in the same way as the first group selector, whereupon the connection is extended to a third group selector which, on the sequence switch FS having been actuated once more by the impulse relay IR, is actuated in like mannerby means of two combination impulses corresponding to the third digit of the subscribersnumber. In

this manner the switching progresses by successively switching in a new row of keys until the switching operation has been completed, when a current path 49, Fig. 1, is

closed through the relay BR cutting off the relays BR and BR, and breaking the circuit of the relay TR and NR,. The latter relay then breaks the circuit of the operators connecting relay DR. Thus t e operators 3 position isentirely separated from the trunk line FL and all relays belonging to the operators position are rendered currentless. The connection is then maintained over the above-mentioned current path 39, the latter having been extended thr ugh the connecting relays of the various switc ing sections, according to the progression of the switching operation.

What we claim as new and desire to secure by Letters Patent of the United States 1s-:

1. A switching arrangement for automatic or semi-automatic telephone plants designed to operate on a code system comprising, group and line selectors, means for'sending out impulse combinations and actuating a number of contact groups in the impulse circuit corresponding to the various digits of the number system employed, a number. switch for partly controlling the circuits of said means, an'd a sequence switch for partly controlling and regulating the actuation of the said means in proper succession so that the impulse signals corresponding to the difi'erent digits of the subscribers number are sent out in due order as the switch operation progresses.

.2. A switching arrangement for automatic or semi-automatic telephone plants designed to operate on a code system comof code relays for sending out impulse combinations and actuating a number of contact groups in the impulse circuit com- .prismg, group and line selectors, a number tion of the code relays in proper succession so that the impulse signals corresponding to the different digits of the subscribers number are sent out in due order as the switch operation progresses. I

3. A switching arrangement for automatic or semi-automatic telephone plants designed to operate on a code system comprising,

out impulse combinations and actuating a number of contact groups in the impulse circuit corresponding to the various digits of "the number system employed, a key boardfor partly controlling the circuits of said means, and a sequence switch for partly controlling and regulating the actuation of the means in proper succession so that the impulse signals corresponding to the different digits of the subscribers number are sent out in due order as the switch operation progresses. v

4. A switching arrangement for automatic or semi-automatic telephone plants designed to operate on a code system comprisin group and line selectors, a number of co e relays for sending out impulses and actuating said selectors and actuating a number of contact groups in the impulse circuit corresponding'to the various digits of the impulse system employed, a key board for partly controlling the circuits of the said relays having the numbers electrically marked thereon, and a sequence switch for partly controlling and regulating the actuation of the code relays in proper succession sothat the impulse signals corresponding to the difl'erent digits of the subscribers number are sent 0ut-in due order as the switch operation pro esses. J

5. A switc ing arrangement for auto-- matic or semi-automatic telephone plants designed to operate on a code system comprising; group and line selectors, a key board including contacts, a sequence switch also including contacts, a number of code relays corresponding to the various digits in the number system employed and controlling the impulse signals and, actuating the number of contact groups in the impulse circuit "corresponding to the various digits in the number system employed, each code relaybeing adapted to be connected for contacts on the key board to any of a number of contacts in the sequence switch, said contacts corresponding to the various digits of the subscribers number, and said sequence switch being adapted to successively actuatesaid contacts. i

6. A switching arrangement for autogroup and line selectors, means for sending impulse signals and actuating a number of contact groups in the impulse circuit corresponding to the various digits in the number system employed, and an auxiliary switch for partly regulating the code relays and for actuating the sequence switch. I y 7. A switching arrangement for automatic or semi automatic telephone plants designed to operate on a code system comprising, group and line selectors, a key board, a sequence switch adapted successively to switch into operation thekeys of said key board so thatimpulses may be sent in due order, a number of code relays corresponding to the various digits of the number system employed and controlling the impulse signals and actuating a number of contact groups in the impulse circuit corresponding to the various digits in the number system employed, and an auxiliary switch for partly regulating the code relays and for actuating the sequence switch. V l

8. A switching arrangement for automatic or semi-automatic telephone plants designed to operate on a code system comprising, roup and line selectors, a key board inc uding contacts, a sequence switch also including contacts, a number of code relays corresponding to the variousdigits in the number system employed and controlling lmpulse signals and actuating the number of contact groups in the impulse circuit,

-matic ,or semi-automatic telephone plants deboard including contacts, a sequence switch also including contacts, a number of code relays corresponding to the various digits in the number system employed and controlling impulse signals and actuating the number'of contact groups in the impulse circuit corresponding to the various digits in the number system employed, each code signal comprising two impulse combinations adapted to be sent out one after the other,

combinations, and an auxiliary switch for regulating the successive sending of the combination impulses and controlling said groups of contacts, said auxiliary switch being controlled by the group and line selectors, and having means whereby the breaking of the current in the impulse circuit will shift the auxiliary switch.

10.A switching arrangement for automatic or semi-automatic telephone plants designed to operate on a code system comprise ing, group and line selectors, a key board including contacts, a sequence switch also including contacts, a number of code relays corresponding to the various digits in the number system employed and controlling impulse signals and actuating the number of contact groups in the impulse circuit corresponding to the various digits in the number system employed, each code signal comprising two impulse combinations adapted to be sent out one after the other, each code relay actuating two groups of contacts corresponding to the two impulse combinations, and an auxiliary switch for regulating the successive sending of the combination impulses and controlling said groups of contacts, said auxiliary switch being controlled by the group and line selectors, and having means whereby the breaking of the current in the impulse circuit will shift the auxiliary switch, said auxiliary switch also being adapted to actuate the sequence switch to advance it to another position after sending two combination impulses.

In witness whereof we have hereunto set our hands in the presence of two witnesses.

GOTTHILF ANSGARXUS BETULANDER. NlLS GUNNAR PALMGREN. Witnesses:

INnz Swanson, S'nNE LARSON. 

